The present invention relates, in general, to electrical circuits, and more particularly, to a novel low noise BICMOS circuit.
The semiconductor industry previously has produced bipolar and complementary metal oxide semiconductor (CMOS) devices on a single integrated circuit. Such combinations typically are referred to as BICMOS. Some of these prior circuits employ an output stage which provides output voltage levels that are compatible with the voltage levels of transistor-transistor logic (TTL). The output stage generally provides a rapid change of current, often referred to as high di/dt, that creates noise thereby disturbing the circuit's operation. In addition, the output stage of such circuits generally consume power even when the circuit is in a static (nonswitching) condition. Such high static power dissipation is detrimental in many applications and especially in battery powered applications.
Accordingly, it is desirable to have a circuit that provides an output voltage level that is compatible with TTL signal levels, that has low static power dissipation, that has a rapid high-to-low transition, and that minimizes noise.